Towards engineering glucosinolates into non-cruciferous plants

Area of Science:

• Plant biochemistry
• Metabolic engineering
• Molecular biology

Background:

• Glucosinolates are plant secondary metabolites with diverse bioactivities, including defense, flavor, and health benefits.
• Engineering glucosinolates into non-cruciferous plants is desirable for expanding their applications.
• The final steps of the benzylglucosinolate pathway are crucial for its biosynthesis.

Purpose of the Study:

• To transfer the last three enzymatic steps of the benzylglucosinolate pathway from Arabidopsis to tobacco.
• To enable the production of benzylglucosinolates in a non-cruciferous plant species.
• To investigate the feasibility of engineering complex metabolic pathways in plants.

Main Methods:

• Utilized a single 2A polycistronic expression construct for simultaneous expression of three genes (C-S lyase, glycosyltransferase, sulfotransferase).
• Transformed tobacco plants with the expression construct.
• Performed in vivo feeding assays with phenylacetothiohydroxamate and enzymatic assays on plant extracts.
• Confirmed protein expression using immunoblots.

Main Results:

• Transgenic tobacco lines demonstrated an enhanced ability to convert phenylacetothiohydroxamate to benzylglucosinolate compared to wildtype.
• Enzymatic activities of the transferred pathway steps were confirmed and enhanced in transgenic plants.
• Immunoblot analysis verified the production of the target proteins from the polycistronic construct.

Conclusions:

• Successfully transferred the final three steps of the benzylglucosinolate pathway to tobacco using a single expression construct.
• Demonstrated the potential for engineering glucosinolate biosynthesis in non-cruciferous plants.
• The results suggest that existing plant detoxification mechanisms may have contributed to the glucosinolate pathway.